Productivity - from Dairy Cows to Farmyard Manure

My problem is that I want to know how things work, whether it is special effects in Star Wars or the machinations of our own universe. When it comes to the economy, I am no less curious. Take productivity, the buzzword of the moment. It's all about inputs of land, workers, machinery and technology say the economic theorists - the amount we get out for what we put in, but is that really it? So I learn about robots and factories and the little voice in my head says ‘no - it must be dirtier and less obvious than that’. And that is when I begin to think about the Christmas dinner table, the supersized turkey, the veg, the largesse, the bountiful table. Everything is bigger better, brighter and different to 50 years ago. Times have changed for the better, or have they?

Don't give up at this point. This is not about returning to the technological dark ages. It is about how we are all, even the economists among us, often ignorant of the ways in which the real economy works.

Agricultural productivity is an example of how productivity is central to all our lives. When I studied economic history at school we were taught how an agricultural revolution preceded and made the industrial revolution possible. If agricultural productivity had not risen, if it wasn't still rising, then we would not have cities, there would be no post-industrial societies like the UK and no industrialising societies like China to fill the shelves of the shops. Look at the graph below and you can see how the share of workers in agriculture in Britain has fallen, freeing people to make other things, invent new products, study more and move to the city.

We calculate agricultural productivity by measuring the output per farm worker, or the output of land - the yield per hectare, for example. Except that even measuring an agricultural yield - the weight of the corn on the cob - is more complicated than people imagine. Is all maize the same, is wheat the same (answer no). And what of the inputs - is all land the same, are all workers equal?

At which point the voice in my head is shouting – yes, but what is actually going on behind the farm gate, tell me how they really increase productivity. Well part of the answer is that they are making everything bigger. Cows, pigs, chickens, the ears of corn, the size of the maize cob. They are all getting fatter and heavier.

Through new combinations of land, machinery, workers and science embodied in fertilisers, pesticides, genetics and breeding techniques - we are getting more out of the land by supersizing the product.

Take a dairy cow. In 1860s Britain the average cow gave about 7 pints of milk a day, by the late 1940s this had risen to 10 pints a day. But in 2015 it was an astonishing 34 pints of milk a day from a single cow. And that is just an average. The increase in yield has been so great that the size of the dairy herd has been reduced.

But for this to occur we have had to change the weight, shape and size of the cows through selective breeding and science. It is not just cows. In the last 30 years the weight of pigs and beef cattle has increased by around 30%. Only sheep seem not be growing.

At this point you might be thinking 'poor cows’ or you may be thinking 'who cares? It's more food’. But there are consequences to this increase in productivity beyond animal welfare. If the fruit and veg get bigger do they have the same nutritional content? Many scientists suspect that they do not. Where does this leave our productivity calculation, if we are producing more but what we are producing is nutritionally inferior? Do we need to consume more to get the same nutritional advantages in 5-a-day?

In addition, the modern agricultural industry’s food and drink products are not the only output. There are the fertilisers and pesticides that are washed into water courses and antibiotics given to animals before slaughter and milking that might inadvertently get into our food.

There is also the ever-growing pile of manure and the great lake of urine that is produced. The more food that goes into the front of our cow then the more comes out of the back. This poses its own problems.

In fact, in weight terms a dairy cow will probably produce more urine and manure than milk. How much? In the UK enough for them all to fill Wembley Stadium several times over each year.

Could this be a perfect organic cycle? Could we turn it into bio-fuel? Perhaps, but in some places there is simply too much of the stuff. Holland today, for example, is suffering waste overload. So, the Dutch Government is now paying some farmers to slaughter their dairy cows because there is just no room for the waste they produce. This should be a problem for economists too. If we want our productivity calculations to be realistic, we also have to include the manure overload. Otherwise we just end up with numbers that are .... - well you get the picture.

MICHAEL HAYNES is Professor of International Political Economy, University of Wolverhampton.